The Cell Transfusion Program is designed to provide platelet and granulocyte transfusion for the therapy of patients with cancer. Studies in the past year have been used as a model; 30 blood processors have demonstrated that this is an efficient means of collecting platelet and granulocytes, and that the cells which are obtained are functionally and morphologically normal. Cryopreservation of platelets obtained using standard platelet pheresis techniques allow frozen platelets to circulate and function hemostatically after transfusion. HL-A matched platelets have been frozen and stored, and a large, computerized donor file of HL-A matched donors has been created. Because of the problems of severe transfusion reactions appearing after the transfusions of granulocytes obtained by filtration of leukopheresis, studies are underway to improve collection and elution procedures. In addition, as part of the cell cryopreservation program, studies on the effects of various cryopreservatives (particularly dimethylsulfoxide) have been carried out. Clinical experience has demonstrated that granulocyte transfusion can be effective in the management of infections, and it has become our policy to use granulocyte transfusions earlier in the course of severe infections.